Transfer presses are built to accommodate a plurality of forming dies arranged in a sequence to produce a completed stamping for each stroke of the press. Generally, the dies are uniformly spaced in the transfer press so that a transfer feed can be utilized to automatically move the work pieces sequentially from one die to the next as the stamping takes place.
Such transfer presses are usually utilized in the stamping of high production items. Frequently, it is desirable to change the die sets to produce other items. In previously known transfer presses, a substantial amount of time has been required for the die changes.
In earlier presses, for example, it was necessary for workmen to go into the press, remove the dies and the transfer fingers which are utilized for the purpose of transferring the material from one die to the other, and place new dies and transfer fingers therein. During such time, the press was shut down.
Later developments have utilized moving die bolsters so that a press could be operating with one set of dies in a bolster while the other bolster was moved out of the press and the dies and transfer fingers replaced thereon. Such a procedure was considerably better than the original and required less down time for the press.
In automated transfer presses, a set of transfer fingers mounted on transfer rails are utilized to move blank material from the stack to the first die and in some instances to move the finished product from the last die to a conveyor. Since these transfer fingers were located on transfer rails positioned on the fixed bed portions of the press, they were not removed with the moving bolsters. Accordingly, the press had to be shut down to permit workmen to enter the press and change out the transfer fingers in the fixed bed portion of the press, resulting in substantial downtime.
An object of this invention is to provide shifting apparatus that moves the transfer fingers from the rails on the fixed bed portion of the press to the rails on the moving bolster so that all of the transfer fingers related to the new dies can be placed thereon while the bolster is in a location out of the press. Once returned to the press, the shifting apparatus moves the appropriate transfer fingers back onto the rails located on the fixed bed of the press. Such an arrangement places the press quickly and automatically in condition for stamping the new product.